93 Mercury 135 EL/PTO Oil Alarm Issue

CapnnaD

Recruit
Joined
Sep 5, 2008
Messages
3
I have a 93 Merc 135 EL/PTO and am having a rather strange issue. I was out on the lake cruising at about 30 MPH or so and got the Beep, Beep, Beep alarm. I know that this is the oil pressure alarm so I immediately shut down and was towed to my trailer by some good samaritans. Upon examination, I noticed that the small reservoir on the outboard (not the main oil tank on the boat) was full. When I removed the cap of the reservoir and the plunger dropped, the alarm stopped. Obviously this is backward of the way the system should operate (the alarm should sound if the plunger drops showing a low oil situation). I took it to a Merc. service center, and they had three guys trying to diagnose the problem for four hours. They tried a new cap on the reservoir and did additional diagnostics to try to isolate the problem, but were unable to. I am a good mechanic, but outboards are a new world for me. Any advice would be much appreciated. I am a new poster here, but have read and learned much from this forum.
Thanks for your help. -Dan
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 93 Mercury 135 EL/PTO Oil Alarm Issue

Welcome to iBoats...

Oil warning system on those engines has multiple parts... Warning module, switch in the cap on the internal tank, hall effect sensor in the oil pump and the engine speed sensor (a wire run from the switch box to the warning module) and the beeper in the control box....

I would start to suspect the module as the culprit, as the others can't create your symptom, only the electronics box...

What did the shop replace?

Chris.....
 

CapnnaD

Recruit
Joined
Sep 5, 2008
Messages
3
Re: 93 Mercury 135 EL/PTO Oil Alarm Issue

The shop tried a new cap, but that didn't solve the problem and they checked resistance on my existing one just to be sure and it checked out. I am not sure of what else they tried, but everytime they replace something that didn't fix the problem, they put my existing part back on. In the end they didn't even want to charge me since they couldn't fix the problem, so I had them change the lower unit oil and water pump just so I could give them some compensation for their time. I originally thought this was going to be an easy fix, but like I said, it left 4 techs scratching their heads.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 93 Mercury 135 EL/PTO Oil Alarm Issue

It's not a complex system... As I said, I'd be looking at the module now....
 

CapnnaD

Recruit
Joined
Sep 5, 2008
Messages
3
Re: 93 Mercury 135 EL/PTO Oil Alarm Issue

I have decided to abandon the oil injection system. Does anyone know of a kit with all necessary plugs and gaskets/o rings necessary to accomplish this. Preferably with instructions. Thanks
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 93 Mercury 135 EL/PTO Oil Alarm Issue

Re: oil injection removal Merc V6 only

You need part number 43453 if it is available. That retains the pump driveshaft bushing and plugs the hole where the pump mounts. Then remove the oil components and the warning module. You'll also need to remove the fitting that the oil tank pressure hose attaches to and plug the hole in the block.

Order three stickers (37-818029 1), one to mount near the fuel fitting on the motor, one for the dash, and one near the fuel fill fitting on the boat. They'll alert the operator that the gas needs to have oil added. One frequent problem we see here regards the infamous "brother-in-law" that forgets to add oil to the gas and roaches the motor.

You should probably replace the fuel lines where the fitting for the oil T's into the fuel line with a single piece of fuel line.

hope the quick clip n paste helps
John
 
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